Pavement markers for delineating highway traffic lanes by means of a series of spaced visible light signals have gained wide spread use. Such markers commonly employ reflector devices which reflect light emanating from the head lights of oncoming automotive road vehicles. In other instances electrically powered lamps are substituted for the reflectors to provide the necessary light source. It is intended herein that "light signal assemblies" as hereinafter described include light reflectors, electrical lamps or other equivalent light sources.
One popularly used highway marker of the prior art described in U.S. Pat. No. 4,147,447 issued Apr. 3, 1979, employs an H-shaped metal body having parallel upwardly extending inclined ramps which are anchored by parallel depending portions extending into elongated slots cut in the pavement of the highway and between which is a horizontal support on which are mounted light reflectors. The ramps serve to guide a snow plow blade or other snow removal equipment upwardly away from and over the top of the reflectors in an effort to avoid impact damage to the reflectors and the anchored marker while leaving the reflectors accessible to wiping action from overpassing vehicle tires.
However, such prior known structures fail to eliminate the damaging impact of a heavy snow plow blade travelling even at moderate speed when it encounters the marker's ramp obstructions, either head on or at an angle. Consequently, although widely used, such elevating ramp type marker structures are frequently torn from their moorings and/or the reflectors are broken and dislodged by snow removal equipment or the impact of normal vehicular traffic, rendering the marker assemblies ineffective for their intended purpose. Of similar importance is the impact damage to the snow plow blades created by the resistive characteristics of the raised ramp-type markers as well as other known marker structures of the prior art which project upwardly from the road surface a substantial distance.